/*
 * Copyright 2022 Apollo Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package com.ctrip.framework.apollo.portal.spi.oidc;

import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;

import org.springframework.security.oauth2.client.registration.ClientRegistration;
import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
import org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository;
import org.springframework.security.oauth2.core.AuthorizationGrantType;

/**
 * @author vdisk <vdisk@foxmail.com>
 */
public class ExcludeClientCredentialsClientRegistrationRepository implements
        ClientRegistrationRepository, Iterable<ClientRegistration> {

    /**
     * origin clientRegistrationRepository
     */
    private final InMemoryClientRegistrationRepository delegate;

    /**
     * exclude client_credentials
     */
    private final List<ClientRegistration> clientRegistrationList;

    public ExcludeClientCredentialsClientRegistrationRepository(
            InMemoryClientRegistrationRepository delegate) {
        Objects.requireNonNull(delegate, "clientRegistrationRepository cannot be null");
        this.delegate = delegate;
        this.clientRegistrationList = Collections.unmodifiableList(StreamSupport
                .stream(Spliterators.spliteratorUnknownSize(delegate.iterator(), Spliterator.ORDERED),
                        false)
                .filter(clientRegistration -> !AuthorizationGrantType.CLIENT_CREDENTIALS
                        .equals(clientRegistration.getAuthorizationGrantType()))
                .collect(Collectors.toList()));
    }

    @Override
    public ClientRegistration findByRegistrationId(String registrationId) {
        ClientRegistration clientRegistration = this.delegate.findByRegistrationId(registrationId);
        if (clientRegistration == null) {
            return null;
        }
        if (AuthorizationGrantType.CLIENT_CREDENTIALS
                .equals(clientRegistration.getAuthorizationGrantType())) {
            return null;
        }
        return clientRegistration;
    }

    @Override
    public Iterator<ClientRegistration> iterator() {
        return this.clientRegistrationList.iterator();
    }
}
